Backdoor Roth Conversion

I contributed 7k (after tax/income) to a non-deductible IRA then converted those dollars to the Roth.

 

Problem: if I put the Taxable amount as $0 in box 2a on1099R form this as a red flag.  That is the only way that I am aware of to get 0$ taxable amount to show on the 1040. Thoughts?